Flyguy... does steam come out all of the holes in the manifold or just one/a few ? I'd like to know what kind of steam distribution you get and how your mash is for temp hot spots.
Yes, all the holes have a relatively fine mist of bubbles coming out of them. I started with only three holes, then added one or two at a time until I no longer had 'big' bubbles.
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The thing I worry about with injecting steam into the line is overheating the wort. And then you always have to worry about having a high enough wort flow rate so as not to over heat it. With direct injection, you don't have to worry about that or hot wort aeration.
Well, that's the one good thing about my 'lightweight' system is that there is very little chance of scorching. I can put my hand in the water about 1/4" from the vents in the manifold before I can feel the direct heat of the steam (although I DEFINITELY felt it when I put my finger over a venting hole). Even the copper manifold stays relatively cool. However, I did notice a tiny bit of warped/melted/scorched plastic on the bottom of the cooler directly under the T connection in the manifold right where the steam line comes in.
Having built and operated a steam injection to circulating wort system, temperature control is as easy as monitoring mixed flow temperature and controlling steam input. Normal flow rate through swagelok tee mixer with a SS screen wire steam diffuser is .83 gpm and water into steam generator is .05 gpm. Having used a pressure cooker and noted the limitations in output, time to steam, and no way to monitor water level and refill under pressure. Have went on to build a continous flow heater/boiler to heat strike water/ make steam for wort heating/ and heat sparge water for fly sparging. With this setup and small volume of water in the coils of the boiler it can reach steam output in about 45-60 seconds, strike and sparge water temps in about 90 seconds. The temperature control is by varying the burner flame since there is no flow control valve in the boiler outlet to cause pressure buildup or explosion. Have tested boiler fittings and coils to 250 PSI and have dry fired to coils to orange heat and fired pump at .25 gpm with cold water to see how the SS tubing held up to abuse, was dissapointed as nothing blew up or leaked.
Yes, success! I posted my results and some pictures to the AG forum here.
Overall, the system worked far better than I expected. It only took 12 minutes to heat 14 lbs of grist in 4.5 gallons of water from 122F to 152F. I probably could have gone faster, too. Brewman - you were right about mash heating faster than water. You were also right about stirring -- I was getting lots of hot and cold pockets initally, but a bit of stirring fixed that. I am wondering now if I had stirred my water in my initial tests whether it would have sped up the heating.
Regardless, this system worked really well -- I love it. It is just really simple and really easy to work with. What a great solution to step-mashing in a cooler! Thanks to brewman ! for the idea and all the help with the design.
...Overall, the system worked far better than I expected. It only took 12 minutes to heat 14 lbs of grist in 4.5 gallons of water from 122F to 152F. I probably could have gone faster, too. Brewman - you were right about mash heating faster than water. You were also right about stirring -- I was getting lots of hot and cold pockets initally, but a bit of stirring fixed that. I am wondering now if I had stirred my water in my initial tests whether it would have sped up the heating...
Did you do anything special to avoid overshooting your target mash temp? Or just a thermometer following your mash paddle while you stirred? I'm very interested in this rig as I've been having chill-haze problems since going AG and I've heard a protein rest can help with that.
My source is Dave Miller's book on that and it's fairly out of date. To be honest I haven't done any further research yet so that may no longer be the case. I've been doing hefe's lately and a protein rest seems like a good idea regardless.
No, I just got lucky and shut it down at the right time for both steps, after watching my thermometer. But the nice thing about this system is that the steam is instant-on, and instant-off. A gas burner would be similar, I suppose. Anyways, you can play it safe by shutting down a little below your target, then give another blast of steam to raise it up if necessary. The valve is also reasonably adjustable, so you could also simply reduce the steam flow when you get near your temp.
I gotta say -- for a $30 add-on to a cheap cooler MLT system, this works very well. You don't need multiple burners and pots and pumps and stands and all that jazz. See my pics here to see how everything can be done in the kitchen on a stove top. The only PITA was the split-boil in two pots, but that wasn't too bad. I will eventually upgrade to a keggle and a single burner system for heating water and bioling the wort.
*laughs Good stuff ! Glad to hear it worked for you, Flyguy !
You just confirmed that steam works better in mash than in water. With water the steam bubbles go straight to the surface. Mash is much thicker and it slows down the bubbles, causing them to break in the mash, releasing their heat. I bet a thick mash would be even better than a thin one.
BTW: Flyguys heating times would have been faster if he had a larger pressure cooker.
One way to get around the hot spots and stirring would be to recirculate the wort while heating. I was thinking about it last night and I'm going to continue injecting steam straight into the mash. On my full size brew system, I'll probably recirc while heating with a pump. If that eliminates the hotspots, this setup is pretty darn good as far as I am concerned.
Like Flyguy said, you don't have to worry about temp overshoots with steam. Just turn off the flow.
Linear Mode
